A conventional apparatus for discriminating primary and secondary batteries is disclosed in Japanese Patent Application No. 187849/1996. In this conventional apparatus, discrimination between primary and secondary batteries is carried out based on whether voltage is present in a discriminating terminal.
In the conventional apparatus for discriminating the primary and secondary batteries, however, there is a disadvantage in that, since the discrimination is always performed based on whether or not voltage is present in the battery discriminating terminal, in some cases, the secondary battery cannot be recharged.
This is because when the residual capacity of the primary battery has become zero, the voltage of the battery discriminating terminal also becomes zero, causing such erroneous discrimination that, even when the loaded battery is a primary battery, the battery is erroneously regarded as the secondary battery.